int main(void){
	int a,b;
	printf("enter two mubers:");
	scanf("%d %d",&a,&b);
	printf("add:%d\n", add(a,b));
	printf("sub:%d\n", sub(a,b));
	printf("mul:%d\n", mul(a,b));
	printf("div:%lf\n",div(a,b));
	return 0;
}
